Hi
If train is cancelled on the date of your Journey then your eticket will be cancelled and refund will be processed but if your return journey is in late summer and by that time if train is running, then you will have to cancel the ticket and cancellation charges according to class will apply. Please note do not cancel your tickets in hurry and wait 3 to 4 days prior to your travel to see how things proceed by that time. If you cancel those tickets in hurry then cancellation charges will apply but if you wait and train is cancelled then only convenience charge is deducted. At present nothing can be said about 18 May so wait atleast till 10 May.